Winchester disc drives are being used in computers to store increasingly large amounts of information the typical Winchester disc drive is a system with a limited number of mechanical parts, including a spindle motor which mounts one or more discs for constant speed rotation, and an actuator carrying a transducer at one end and a voice coil motor at the other and operable in response to commands to the voice coil motor to position the transducer over a selected track to read and write data.
As one of the most expensive elements of a disc drive, as well as being one of the largest and most mechanically complex, many design efforts are intended to minimize the cost and ease of assembly of the spindle motor. This particular invention is especially directed to improving a spindle motor design which incorporates a central connector which extends through the bottom of the shaft and into and through the base of the disc drive, so that external connections can easily be made from below the motor to provide energizing current to the disc drive spindle motor. It is apparent that it is essential to provide a reliable connector from a source of external power to the stator of the spindle motor so that the motor can be reliably energized. A related problem posed by stator motors with such a central connector is how to provide an effective electrical grounding path between the stator and the shaft, without resorting to an unduly complex motor assembly.